Big Block chevy question?

[JBUSAF]

More silly questions!
I bought a block yesterday, the number on it is (3999293), it has Hi Perf Pass and Truck on the back. A check on the internet shows it as a "tall truck 366". Will reqular (I.E. 454) parts go on this block? How big can the bore go? Right now it has a plate that says it was .030 over. A check with my calipers on the top of the bore is about 3.93" and that seems real small for a big block chevy. I really don't understand the difference between a regular and a"Tall" block. Would this build up into a decent motor?
Thanks
JB

[Moneypitt]

Yes, the tall block is a heavy duty truck block. However, the standard BBC stuff won't fit. I'm not sure how big the block will bore, maybe 4.25, but the intakes, and rods are different. You can get spacers for the intake, but I would check for the max bore with someone that knows for sure,(fiat48). A lot of drag guys use only the tall blocks because of the longer rods. although they are getting harder to find.............MP

[Oldsquirt]

If that block is at 3.93" and is already .030" over, you would probably not be able to safely get it to the 454 stock bore of 4.00". That would put you at .100" over the stock bore of that block.

[Fiat48]

There are guys that have said they have done it, but I know of no 366's that would bore to 4.250 size (which is std 454 bore). Since you own it..first thing to do is have it sonic checked. If it would go to 454 size then to me it sould be worth building.
The tall deck 366 and 427 blocks are .400 taller. 10.200 ht. To compensate that tall height, your piston/rod combo has to be .400 taller. I do this a lot by using a .400 long rod and a standard pin height 454 piston. But there are other ways.
Because of the tall height, you have to use spacer plates under a standard intake or use an intake specifically made for tall deck. Next problem is dsitributor height. Some of the tall deck aftermarket intakes are machined down in the distributor area so a standard distributor will work. And there are also tall deck distributor bases made for Vertex and mallory ignitions. Also there are some "sliding colar" distributors out there you can adjust and make work in either a tall deck or a low deck.
Those are about the only issues you will run into. All easily cured.

[DansBlown73Nordic]

I sure hope you didn't pay alot for it....

[DansBlown73Nordic]

All Tall Decks have a forged steel crank and a set of heavy duty truck rods. They should be 7/16 rod bolts.

[Oldsquirt]

Originally posted by Fiat48
There are guys that have said they have done it, but I know of no 366's that would bore to 4.250 size (which is std 454 bore).
Originally posted by OLDSQUIRT
.....454 stock bore of 4.00"......
OOPS. How'd I forget that? :D

[JBUSAF]

Thanks for the information, if I decided to build it, I will have it checked out to see what bore would be safe. So basically it would require a "Tall" deck Intake, distributor and proper piston/rod configuration. Is their any benefit to the tall deck that would warrant its use in a motor of around 427 inches? What bore size would this block need to handle for that? Are the 454/427 cranks the same or is the 454 .250 longer throw? The block looks like it is in good shape and it has the 4 bolt mains, I just don't know if it worth building or maybe it would make a strong motor for the Suburban when the 350 gets worn out!
Thanks
John B.

[Fiat48]

A 366 has a 3.935 bore size and a 3.76 stroke (427 crank same). You gotta bore that thing over 1/4" just to get to 454 bore size. If it made it (and I doubt it) you'd have 427 inches with the 3.76 stroke or 454 inches with the 4" stroke.
My advise is to have it sonic checked (if you know someone who can do it local) and if it won't go the 4.250 bore size...resell it. Just not worth the trouble and expense to build a small BBC. You'd be better off with a 396 or 402.

[Cs19]

I agree with Fiat, have it sonic checked its cheap insurance, I sonic checked a few blocks a while back, even standard ones and ended up not using a couple of them.You may be surprised with the results. If you not familiar with the test, your just checking the cylinder wall thickness. I know a guy in OC that does the test for under 100 bucks (I think $75). Let me know if you need his number, it only takes 10 minutes.Dont go boring that block without doing the test.

[damnyankee2001]

I have a brand new set of 427 truck pistons for sale. If you decide to build up your block let me know if you're interested.